OP0291 SCORING STRUCTURAL DAMAGE IN RHEUMATOID ARTHRITIS BY ULTRASOUND: RESULTS FROM A DELPHI PROCESS AND WEB-RELIABILITY EXERCISE BY THE OMERACT US WORKING GROUP
Authors: P. Mandl, I. Gessl, G. Filippou, S. Sirotti, L. Terslev, C. Pineda, H. Keen, M. Backhaus, D. A. Bong, E. Cipolletta, P. Collado, C. Dejaco, A. Delle Sedie, C. Duftner, H. B. Hammer, A. Iagnocco, Z. Karim, I. Möller, E. Naredo, W. A. Schmidt, M. Szkudlarek, G. Tamborrini, P. C. Wong, E. Filippucci, P. Balint, M. A. D’Agostino
Journal: Annals of the Rheumatic Diseases (2022)

Background Structural damage in rheumatoid arthritis (RA) includes bone erosion, cartilage change, and joint malalignment; historically evaluated with conventional radiography. Ultrasound (US) has been shown to be a valid tool for evaluating both cartilage change and bone erosion. Objectives To obtain agreement on definitions and develop semiquantitative scoring systems for assessing structural damage by US and to validate these in a web-based reliability exercise. Methods A Delphi survey of statements was prepared by an OMERACT US Working Group task force (USWG) based on a previously published systematic literature review (1) and circulated between group members, including definitions on normal US appearance of joint components, definitions of elementary lesions and scoring systems for bone erosions and joint malalignment. Definitions and a US scoring system for scoring cartilage change were recently developed and validated by the USWG (2) After agreement was achieved (≥75% of grades 4-5 on 1-5 Likert scale) on the statements, still images of metacarpophalangeal and proximal interphalangeal joints 2-5 in healthy controls and in RA patients with varying degrees of pathology were acquired by the USWG members. A dataset of 100 anonymized images, representing various grades of the 3 components of structural damage was created and utilized in 2 rounds of a web-based exercise. Intra- and inter-reader reliability of the scoring systems was assessed by kappa statistics. Results 19 USWG members needed 4 Delphi rounds to reach agreement on a total of 9 statements. 4/12 statements were approved in the first, 2/6 in the second, 1/5 in the third and 2/2 in the fourth round. Final scoring systems and representative images are shown in Table 1 &amp; Figure 1. 22 members participated in the web-based reliability exercise. The intra-reader reliability was almost perfect for bone erosion (kappa: 0.87) and cartilage change (kappa: 0.83) and substantial for malalignment (kappa of 0.72). The inter-reader reliability was almost perfect for bone erosion (kappa: 0.85), and substantial for cartilage change (kappa: 0.79) and malalignment (0.62). Table 1. Final definitions of scoring systems of elementary lesions of structural damage in rheumatoid arthritis Agreement Bone erosion A 4-grade semiquantitative scoring system can be used to score erosions as follows: grade 0. intact cortical bone; grade 1. single small erosion (diameter: ≤2mm); grade 2. single large erosion (diameter: &gt;2mm) or 2 small erosions; grade 3. 2 large erosions or ≥3 erosions, regardless of size. Both longitudinal and transverse scans should be considered, and the largest measure chosen for each erosion. 100% Cartilage change A 3-grade semiquantitative scoring system can be used to grade hyaline cartilage change as follows: grade 0. normal cartilage; grade 1. minimal change: focal thinning or incomplete loss of cartilage; grade 2. severe change: diffuse thinning or complete loss of cartilage. 80% (2) Malalignment A 3-grade semiquantitative scoring system can be used to grade malalignment as follows: 0. normal alignment; 1. subluxation or partial dislocation, where the two bone endings are malaligned so that one bone ending is dislocated from its normal position, but still within the articulation; 2. luxation or total dislocation, where the luxated bone ending moves beyond the articulation and the opposing bone ending. Bone position may be compared with a contralateral or similar intact joint if available. 94% Figure 1. Representative images of the scoring systems for bone erosion (A), cartilage change (B) and malalignment (C ) Conclusion This first attempt to create a composite US instrument based on scoring systems encompassing all aspects of structural damage, demonstrates that US is a reliable tool for evaluating and scoring bone erosion, cartilage change and malalignment in the finger joints of RA patients. References [1]Gessl I, et al. Semin Arthritis Rheum. 2021 Jun;51(3):627-39. [2]Mandl P, et al. Rheumatology (Oxford). 2019 Oct 1;58(10):1802-11. Disclosure of Interests Peter Mandl Speakers bureau: AbbVie, Janssen, Lilly, Novartis, Consultant of: AbbVie, Janssen, Lilly, Novartis, Grant/research support from: AbbVie, BMS, Novartis, Janssen, Lilly, MSD, UCB, Irina Gessl: None declared, Georgios Filippou: None declared, Silvia Sirotti: None declared, Lene Terslev Speakers bureau: Novartis, Pfizer, UCB, Janssen, GE, Carlos Pineda: None declared, Helen Keen Speakers bureau: Roche, AbbVie, Janssen, Consultant of: Sanofi, Marina Backhaus: None declared, David Andrew Bong: None declared, Edoardo Cipolletta: None declared, PAZ COLLADO: None declared, Christian Dejaco Speakers bureau: Roche, AbbVie, Sanofi, Lilly, Pfizer, Novartis, Janssen, Galapagos, Consultant of: Roche, AbbVie, Sanofi, Lilly, Pfizer, Novartis, Janssen, Galapagos, Andrea Delle Sedie Speakers bureau: Abbvie, Amgen, Lilly, MSD, Novartis, UCB, Paid instructor for: Abbvie, Amgen, Lilly, MSD, Novartis, UCB, Consultant of: Abbvie, Amgen, Lilly, MSD, Novartis, UCB, Christina Duftner: None declared, Hilde Berner Hammer: None declared, Annamaria Iagnocco: None declared, Zunaid Karim: None declared, Ingrid Möller Speakers bureau: Bristol-Myers Squibb, Ibsa, Pfizer, Galapagos, Esperanza Naredo Speakers bureau: Abbvie, Pfizer, Lilly, Novartis, Janssen, Celgene GmbH, Paid instructor for: Novartis, Consultant of: Novartis, Lilly, Grant/research support from: Lilly, Pfizer, Wolfgang A. Schmidt: None declared, Marcin Szkudlarek: None declared, Giorgio Tamborrini: None declared, Priscilla C Wong: None declared, Emilio Filippucci Speakers bureau: AbbVie, Amgen, Bristol -Myers Squibb, Janssen-Cilag, Lilly, Novartis, Pfizer, Roche, Union Chimique Belge Pharma, Peter Balint Speakers bureau: Abbvie, Janssen, Lilly, Novartis, Maria-Antonietta D’Agostino: None declared